Immune Patho

Question 1

Characteristics of SCID and AIDS

Answer 1

Total lack of T and B cells (sometimes NK).

HIV —> AIDS. Results in a lack of T helper cells = immunosuppression.
- opportunistic infections.

Question 2

What is hypersensitivity?
Allergic hypersensitivity?
Immediate hypersensitivity?
Delayed hypersensitivity?

Answer 2

Over-reaction of the immune system.
Allergic - hypersensitivity to a particular antigen.
Immediate - minutes, IgE mediated & involves mast cells, basophils & T helper 2 cells.
Delayed - T helper 1 cell mediated. Cytokine synthesis stimulating inflammation.

Question 3

What are the 3 autoimmune diseases?

Answer 3

Crohn’s - inflammatory bowel disease (can be along GI tract).
Myasthenia Gravis - own antibodies attack own acetylcholine receptors causing internalisation & destruction. Decrease synaptic transmission.
SLE - autoantibodies and immune complexes cause destruction of multiple tissues. DNA, RNA and other nuclear proteins are targeted within the cell nuclei.

Question 4

What is the pathophysiology of transplant rejection and graft vs host disease?

Answer 4

Transplant rejection - Bodies immune system attacks MHC of transplant. Involves both cell and antibody (preformed). Acute = cell mediated. Delayed = fibrosis.

GVHD - graft T cells responsible.